birch bark covering over sinew, how do you do it?

[stuckinthemud]

OK, so, I have never covered or backed a bow and I have never worked with bark in any form.  Its Spring and time to harvest some birch bark, first question, is Silver Birch OK? Do I just go for a walk in the woods and pick off bark peeling naturally or do I have to cut out strips - presumably vertical strips so as not to girdle the tree???  Once I have the bark, does it need soaking before use?  Then, I seperate the layers down to a single layer, but, is the bark cut into small rectangles, or long strips, and how exactly do you cover a bow, oh, and hide glue, is it OK for this task?

Sorry to be a helpless newbie about this but all advice is needed and welcome.

Thanks in advance,

Andrew

[EdwardS]

I'll tell you what I know. 

Yes, hide glue works best.  Some bows are covered with one long strip, some are covered with little squares, some are covered with mosaics.  That's up to the bow's design.  Some cultures soak the birchbark in salt water, some just peel it and put it on.  Birchbark should be peeled from the tree while it's attached.  I don't think that peeling bark is usable, but I'm unsure on that point.  Paper birch is the one I know works, but I'm betting silver birch will work. 

If you get some bark that works, I should be interested.

[PatM]

 You only need the freely peeling stuff for a bow. No need to wait for spring since you shouldn't be stripping the bark down to the inner bark anyway.  Trees which are dead and down actually provide the best bark since the bark seems to fuse together better and be more elastic.  The elasticity of the bark varies widely from tree to tree.  Some is very brittle and others may stretch like tape.

 You can put it on in any number of ways.  The easiest is probably in shorter sections slightly overlapped.

 Hide glue is great since you can warm up the bark and glue and re-position and work out air bubbles easier.

 Peeling it apart and leaving it a couple of layers thick is easier to lay it on.  Settle for pieces which are well fused together so it doesn't separate later.

[EdwardS]

Thanks for filling in the gaps in my knowledge Pat.  The strokes leave me with holes in my recollection. 

[Dances with squirrels]

It's removed around the circumference of the tree, not vertically. Peeling the outer bark won't hurt the tree as long as some inner bark and all cambium layer is intact.

I stripped bark from a pin cherry log at a sawmill two weeks ago. I had permission. I cut them 2-3" wide and then trimmed them nice and straight and 2" wide when I got home. I then removed much of the inner bark and layed heavy boards on them so they'd stay flat. There's a lot of waste due to how the bark grew in this one. I wish I'd have gotten more.

[PatM]

If you were making bark containers or say a quiver you'd want to strip the bark deeper but for just a sinew covering using birch there's no need to take more than what's naturally separating as the tree grows.

[stuckinthemud]

Found a downed stem not too far rotted, peeled this piece; is it what i should be looking for, its thinner than paper?

[maitus]

http://www.atarn.org/chinese/making_chinese_bow/making_bow.htm

Dont use old bark, its not moisture resistant

[simk]

the easy way 
https://sagaan.de/birkenrinde/shop/birkenrinde-zum-verarbeiten/birkenrinde-in-platten/

[stuckinthemud]

Thanks simk but my house is a mile from a large birch wood  and my place of work is surrounded by an even larger birch forest. Maitus, following your advice I tested the sample and ir is waterproof except for the pores but a coat of varnish/acrylic/oil paint would deal with that I should think?

[PatM]

You want it more obviously looking like paper strips.   Older  bark is just fine and easily as water resistant unless it is actually almost rotted.  That takes years.  I've salvaged bark from trees down for three years.

[stuckinthemud]

So is this too thin? I hadn't bothered to trim it to shape as I didnt have scissors with me?  The bark was literally falling to pieces as i peeled it, this is the second layer as the first layer just flaked away,

[PatM]

No, it's just not a good sample.  The good stuff is clear and peels easily into layers.  It should be almost like drywall tape and ideally slightly stretchy when pulled before it breaks in tension.

[Marc St Louis]

I wouldn't use bark from a dead tree especially if you have access to live trees.  As Pat says, some trees have elastic bark and others it is brittle.  You should test before putting it on.  The bark can be separated into very thin layers.  I wouldn't use anything thicker than 1/32" thick

[stuckinthemud]

Thanks Pat, this sample is transparent, slightly stretchy and about the same thickness as onion skiin or bamboo leaves. I think its Downy Birch (B Pubescens), which is brown barked. Its not pretty to look at but I'm going to paint it. If Pubescens isnt suitable I can keep looking for a fallen silver or paper birch, it wont take long to find something else.